Ma J, Przibilla E, Hu J, Bogorad L, Ptashne M
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Nature. 1988 Aug 18;334(6183):631-3. doi: 10.1038/334631a0.
GAL4 is a transcriptional activator found in yeast. Two distinct functions of the protein are required for its activity: one directs sequence-specific DNA binding, and another interacts with some other component of the transcriptional machinery, for example, RNA polymerase II or a TATA-binding protein. Two short regions of GAL4 function as 'activating sequences' when attached to the DNA-binding portion of GAL4 and these regions can be replaced by a large number of peptides encoded by Escherichia coli genomic DNA fragments or by a synthetic peptide designed to form an amphiphilic alpha-helix. All of these activating sequences, like that found in another yeast activator, GCN4 bear an excess negative charge. GAL4 and its derivatives that are active in yeast stimulate transcription in mammalian cells when GAL4 binding sites are introduced upstream of a mammalian gene; similarly, GAL4 activates transcription in Drosophila cells. Here we show that GAL4 derivatives stimulate gene expression in plant cells.
GAL4是一种在酵母中发现的转录激活因子。该蛋白的活性需要两种不同的功能：一种功能指导序列特异性DNA结合，另一种功能则与转录机制的某些其他成分相互作用，例如RNA聚合酶II或TATA结合蛋白。当GAL4的两个短区域连接到GAL4的DNA结合部分时，它们作为“激活序列”发挥作用，并且这些区域可以被大量由大肠杆菌基因组DNA片段编码的肽或由设计形成两亲性α-螺旋的合成肽所取代。所有这些激活序列，就像在另一种酵母激活因子GCN4中发现的那样，都带有过量的负电荷。当在哺乳动物基因上游引入GAL4结合位点时，在酵母中具有活性的GAL4及其衍生物会刺激哺乳动物细胞中的转录；同样，GAL4会激活果蝇细胞中的转录。在这里我们表明，GAL4衍生物会刺激植物细胞中的基因表达。
